Question

If a bird is moving at a velocity of 70 km/h east and a car is moving at a velocity of 80 km/h east, what is the velocity of the bird relative to the passengers in the car?\

A. 10km
B. 10km/h
C.10km/h west
D.70 km/h east

Answer 1

If they both move in the same direction, you subtract the velocities. If they both move in opposite directions, you add the velocities. In this problem, they both move east, so the relative velocity is vr = (velocity of bird) - (velocity of car) vr = (70 - 80) km/h east = -10 km/h east = 10 km/h west